1. Statement of the Technical Field
The inventive arrangements relate to electronic devices, and more particularly to systems and method for providing wireless health monitoring for locator beacons and batteries thereof.
2. Description of the Related Art
Most commercial and military aircraft, as well as many civilian aircraft, carry Flight Data Recorders (FDRs) and/or Cockpit Voice Recorders (CVRs). During normal flight operations, the FDR records specific aircraft performance parameters, such as air speed, altitude, vertical acceleration, time, magnetic heading, control-column position, rudder-pedal position, control-wheel position, horizontal stabilizer and fuel flow. The CVR records cockpit voices and other audio such as conversations between ground control and flight crew. Each of the recorders has an enclosure containing an electronic interface, processing circuits and a Crash Survivable Memory Unit (CSMU). The CSMU contains non-volatile memory for storing the flight data and voice data.
In the event of a crash, most of the FDR chassis and inner components may be damaged. However, the CSMU is designed to survive the impact, potential ensuing fire, submersion, and aftermath of various environmental conditions. For example, under the EUROCAE ED-112 standard, the FDR is required to withstand an impact of 3600 g and temperatures up to 1000° C. The data stored on the CSMU should still be recoverable.
Popularly known as the “black box” and regulated by International Civil Aviation Organization (ICAO), FDRs are crucial in investigating and understanding aircraft accidents. In fact, the recovery of the black box is second only to the recovery of survivors and victims. FDRs can also be used to study air safety, material degradation, flying procedures, and jet engine performance. The outer housings of the FDRs are painted bright orange for ready identification. The FDRs are generally located in the tail section of aircrafts to maximize survivability.
To assist in recovery of the FDR, a locator beacon is provided with an FDR. The locator beacon is a self-contained device, i.e., it contains a battery (e.g., a lithium battery) and beacon control circuit necessary to maintain operation. The locator beacon can be manually activated or automatically activated. The locator beacon can be automatically activated by water immersion, high acceleration of a vehicle or craft and/or impact. Once activated, the locator beacon requires no interaction or support from the main body of the FDR. During operation, the locator beacon emits ultrasonic pulses which can be tracked by equipment operated by rescue crews.
The locator beacon is a separate unit, typically cylindrical in shape, which is bolted to an external or internal surface of a housing of the FDR. Notably, there are various advantages to disposing the locator beacon inside the FDR. For example, a locator beacon internal to the FDR may be protected from damage due to the g-forces of the impact, heat of ensuing fire, submersion, and other environmental conditions. In contrast, a locator beacon external to the FDR may be susceptible to g-forces of the impact, heat of ensuing fire, submersion, and other environmental conditions.
The locator beacon is battery operated to ensure functional operation after a crash. The locator beacon and/or battery must be replaced periodically because FDRs have no means of monitoring the charge state of the battery or to recharge the battery. Thus, the service interval of the FDR is in part limited by the locator beacon battery. The service interval is typically a number of years (e.g., 1-2 years). Personnel must physically inspect the locator beacon to determine a recommended replacement time for the locator beacon and/or battery. The recommended replacement time is determined based on the expected life of the battery (e.g., 6 years). The recommended replacement time is often printed on a label disposed on an outer surface of the locator beacon. If the label is not visible upon inspection of the locator beacon, then the locator beacon must be removed from its mounting bracket. If the recommended replacement time indicates that it is not time to replace the locator beacon and/or its battery, then a manual battery check process may be performed to determine one or more conditions of the battery (e.g., a battery charge capacity and/or a battery voltage level).
Despite the advantages of the above described health monitoring techniques of the locator beacon and its battery, they suffer from certain drawbacks. For example, the health monitoring and battery voltage measurements of the locator beacons requires access to the beacon. The location of the beacon may be difficult to access. Also, the health monitoring of the locator beacon is a manual process, which is relatively time consuming and expensive.